In recent years, image classification/recognition has become an active area of research. In particular, many approaches have been developed to boost performance and robustness of generic object-based image classification by using context information (i.e. concept depending on situations and conditions in the real world, such as human behaviors and object positions. For example, co-occurrence relationships, relative positions, relative scales, and the relationships between a background and a foreground can be the context) (see Non-Patent Literatures 1 through 4).